ext4: make ext4_init_dot_dotdot for inline dir usage

Currently, the initialization of dot and dotdot are encapsulated in
ext4_mkdir and also bond with dir_block. So create a new function
named ext4_init_new_dir and the initialization is moved to
ext4_init_dot_dotdot. Now it will called either in the normal non-inline
case(rec_len of ".." will cover the whole block) or when we converting an
inline dir to a block(rec len of ".." will be the real length). The start
of the next entry is also returned for inline dir usage.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 71 insertions, 44 deletions

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 88e9a2c7e328..edb9f10c1455 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2230,21 +2230,87 @@ retry:
         return err;
 }
 
-static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
+                          struct ext4_dir_entry_2 *de,
+                          int blocksize, int csum_size,
+                          unsigned int parent_ino, int dotdot_real_len)
+{
+        de->inode = cpu_to_le32(inode->i_ino);
+        de->name_len = 1;
+        de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
+                                           blocksize);
+        strcpy(de->name, ".");
+        ext4_set_de_type(inode->i_sb, de, S_IFDIR);
+
+        de = ext4_next_entry(de, blocksize);
+        de->inode = cpu_to_le32(parent_ino);
+        de->name_len = 2;
+        if (!dotdot_real_len)
+                de->rec_len = ext4_rec_len_to_disk(blocksize -
+                                        (csum_size + EXT4_DIR_REC_LEN(1)),
+                                        blocksize);
+        else
+                de->rec_len = ext4_rec_len_to_disk(
+                                EXT4_DIR_REC_LEN(de->name_len), blocksize);
+        strcpy(de->name, "..");
+        ext4_set_de_type(inode->i_sb, de, S_IFDIR);
+
+        return ext4_next_entry(de, blocksize);
+}
+
+static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
+                             struct inode *inode)
 {
-        handle_t *handle;
-        struct inode *inode;
         struct buffer_head *dir_block = NULL;
         struct ext4_dir_entry_2 *de;
         struct ext4_dir_entry_tail *t;
         unsigned int blocksize = dir->i_sb->s_blocksize;
         int csum_size = 0;
-        int err, retries = 0;
+        int err;
 
         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
                 csum_size = sizeof(struct ext4_dir_entry_tail);
 
+        inode->i_size = EXT4_I(inode)->i_disksize = blocksize;
+        dir_block = ext4_bread(handle, inode, 0, 1, &err);
+        if (!(dir_block = ext4_bread(handle, inode, 0, 1, &err))) {
+                if (!err) {
+                        err = -EIO;
+                        ext4_error(inode->i_sb,
+                                   "Directory hole detected on inode %lu\n",
+                                   inode->i_ino);
+                }
+                goto out;
+        }
+        BUFFER_TRACE(dir_block, "get_write_access");
+        err = ext4_journal_get_write_access(handle, dir_block);
+        if (err)
+                goto out;
+        de = (struct ext4_dir_entry_2 *)dir_block->b_data;
+        ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
+        set_nlink(inode, 2);
+        if (csum_size) {
+                t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
+                initialize_dirent_tail(t, blocksize);
+        }
+
+        BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
+        err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
+        if (err)
+                goto out;
+        set_buffer_verified(dir_block);
+out:
+        brelse(dir_block);
+        return err;
+}
+
+static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+        handle_t *handle;
+        struct inode *inode;
+        int err, retries = 0;
+
         if (EXT4_DIR_LINK_MAX(dir))
                 return -EMLINK;
 
@@ -2268,47 +2334,9 @@ retry:
 
         inode->i_op = &ext4_dir_inode_operations;
         inode->i_fop = &ext4_dir_operations;
-        inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
-        if (!(dir_block = ext4_bread(handle, inode, 0, 1, &err))) {
-                if (!err) {
-                        err = -EIO;
-                        ext4_error(inode->i_sb,
-                                   "Directory hole detected on inode %lu\n",
-                                   inode->i_ino);
-                }
-                goto out_clear_inode;
-        }
-        BUFFER_TRACE(dir_block, "get_write_access");
-        err = ext4_journal_get_write_access(handle, dir_block);
+        err = ext4_init_new_dir(handle, dir, inode);
         if (err)
                 goto out_clear_inode;
-        de = (struct ext4_dir_entry_2 *) dir_block->b_data;
-        de->inode = cpu_to_le32(inode->i_ino);
-        de->name_len = 1;
-        de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
-                                           blocksize);
-        strcpy(de->name, ".");
-        ext4_set_de_type(dir->i_sb, de, S_IFDIR);
-        de = ext4_next_entry(de, blocksize);
-        de->inode = cpu_to_le32(dir->i_ino);
-        de->rec_len = ext4_rec_len_to_disk(blocksize -
-                                           (csum_size + EXT4_DIR_REC_LEN(1)),
-                                           blocksize);
-        de->name_len = 2;
-        strcpy(de->name, "..");
-        ext4_set_de_type(dir->i_sb, de, S_IFDIR);
-        set_nlink(inode, 2);
-
-        if (csum_size) {
-                t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
-                initialize_dirent_tail(t, blocksize);
-        }
-
-        BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
-        err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
-        if (err)
-                goto out_clear_inode;
-        set_buffer_verified(dir_block);
         err = ext4_mark_inode_dirty(handle, inode);
         if (!err)
                 err = ext4_add_entry(handle, dentry, inode);
@@ -2328,7 +2356,6 @@ out_clear_inode:
         unlock_new_inode(inode);
         d_instantiate(dentry, inode);
 out_stop:
-        brelse(dir_block);
         ext4_journal_stop(handle);
         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
                 goto retry;